Kohler CH 16 valves, closure, and clearance

Hello
I have a Kohler CH 16 S in a cub cadet.It's actually my 97 year old parents' tractor. It wouldn't start so I tore it apart and found a blob of stuff burnt on the exhaust valve. I scraped the burnt stuff off the valve and used a piece of emery cloth to clean up the valve and seat. Everything in the engine looks really good... especially for it's age no scarring in the cylinder no nothing ...looks really good.


In the manual , it describes a leak down test, which is how I came upon the valve in the first place. When I was putting the tractor back together, it did not seem that the valves were sealing due to the rocker arm holding them down so I put washers under them until the valve closed. Upon running it, it seemed to run well, but after about an hour started smoking like crazy. I tore it apart again, and there was oil everywhere in the engine... I believe it came thru the carburetor from the breather.
I replaced rings, valve oil seals, and head gasket and am putting it together again.

I removed the washers I put in under the rocker arms in the first place, but here is my question: I understand that the hydraulic lifters must be empty of oil... how do I make sure that is occurring and how do the valves close when the rocker arms seem to not have any clearance and hold them open?

I'm thinking ( hoping ) that the washers I put under the rockers, or the rings were the culprit in the excess oil everywhere, but I don't see how the leakdown test would work, or how the valves would seal with the rocker arms being tight. Seems like there should be some clearance between the rocker arms and the valves... Shimming the rocker arms seemed to me to be a good idea, allowing the valves to close for sure because the rocker arms were about a half a red hair loose on the valves

Could someone please advise me on this ?

Thank you .

Many of your assumptions are causing you problems, because your assumptions are wrong. First, hydraulic lifters should stay full of oil. Second, there should be no clearance between the valve stem and rocker arm. Third, in a properly set-up valve train the valve springs close the valves, sealing the cylinder. Fourth, I don't understand where you are inserting washers, but there should bem not reason for them. Finally, when you reassembled the engine, did you allow the lifters to stabilize? There is a procedure in the service manual. You need to go back and reread the section in your manual on how to assemble and adjust a hydraulic lifter valve train.

Rivets said:

Many of your assumptions are causing you problems, because your assumptions are wrong. First, hydraulic lifters should stay full of oil.

Click to expand...

Bleeding the Lifters
To prevent a possible bent push rod or broken rocker
arm, it is important to bleed any excess oil out of the
lifters before they are installed.
1. Cut a 50-75 mm (2-3 in.) piece from the end of an
old push rod and chuck it in a drill press.
2. Lay a rag or shop towel on the table of the drill
press and place the lifter, open end up, on the
towel.
3. Lower the chucked push rod until it contacts the
plunger in the lifter. Slowly pump the plunger
two or three times to force the oil out of the feed
hole in the side of the lifter.

Rivets said:

Second, there should be no clearance between the valve stem and rocker arm.

Click to expand...

If there is no clearance how do you know the valve is closed?

Rivets said:

Third, in a properly set-up valve train the valve springs close the valves, sealing the cylinder.

Click to expand...

I guess by posting I was hoping that someone who knew would instruct me how to do that, rather than just make condescending remarks.

Rivets said:

Fourth, I don't understand where you are inserting washers, but there should bem not reason for them.

Click to expand...

I inserted washers under the rocker arms to raise them enough so that they did not compress the valve spring because it seemed that the rocker arm was holding the valve open as there was tension on the rocker arm from the valve spring.... one of my incorrect assumptions.... according to you. I would be interested in knowing how the valve could be completely closed when the rocker arm is under spring tension from the valve spring

Rivets said:

Finally, when you reassembled the engine, did you allow the lifters to stabilize? There is a procedure in the service manual.

Click to expand...

Is this the part you mean?

Before starting the engine, turn the engine over
slowly by hand. If it can be turned over
completely and compression is noted, the lifters
have bled down sufficiently and the engine can
be test run. If, however, it can not be turned over
completely (locks up at some point), return the
piston to TDC between the intake and exhaust
strokes and wait ten minutes to allow the lifters
time to bleed down then check for compression
again. If started with extended lifters, bent push
rods or other engine damage could occur.

Rivets said:

You need to go back and reread the section in your manual on how to assemble and adjust a hydraulic lifter valve train.

Click to expand...

Well, it's for sure I'm going to learn nothing from your condescending bloviation. I'm sorry I bothered you. perhaps someone who is willing and able to provide some useful information will respond. I thank God you were never my grease monkey instructor.

Telling you-you did something wrong is not condescending it is just the truth. He is trying to figure out what you did so he can help you fix it. You would be wise to listen to him.

Sorry to bother you, as I guess you know more than me about engines. This grease monkey will get out of the way and let an expert help you. Good Luck.

Well, lets see.
I could spend hours typing trying to explain to you how hydraulic lifers actually work and why you have to install them empty followed by all of the relivant theory or I could use the same hour out in the workshop making money.
Hard decision isn't it.'

So my advice as I have no time for people who have no idea what they are doing then start to throw abuse at those who seek to help them FOR FREE is,
Go to Tractor Data ( google it yourself ) and find the John Deere section
Troll through all of them till you find one that uses a Kohler Ch engine ( size is not important )
Next go to the Jon Deere web site and BUY the relevant work shop manual . I think they call them "Technical Manuals" about $ 40 as a download or $ 100 in paper.
They were written by people who got paid to write a repair manual for people just like you who can understand what they read but have no idea about what they are doing or how it actually works.
Each every section starts off with a "theory of Operation" which explains how the bits work together.
and the tip is look for the oldest mower with a CH engine because JD was in fact paying some one to write them in the latter years they just included the Kohler manual ( which you already have ) rather than rewriting it in a better way.
Good luck
And with an attitude like yours you will need it.

I too have a CH16. Mine will not start, and I think there may be an issue with my Hyd. lifters. Originally my mower would not start and I wrongly can to the conclusion that it was a bad head gasket. I tore it down and replaced the head gasket even though the original was still good. I closely inspected the head and couldn't find anything out of sorts I did not bleed the lifters ad put it back together and it will not start. I have ordered a leak down test kit but it was back ordered for 20 days.I have good spark. Tried starting fluid thru the carb and gas in the spark plug hole. No start. Took valve cover off and manually turned engine. both valves look to be opening and closing correctly. When both valves are closed and you continue to turn the engine over there is a slight leak of air bt I am told that is from the compression release working correctly. Any suggestions on where to go from here would be greatly appreciated

So the motor would not start, so you replaced the head gasket and it still doesn't start. Original problem still there. Does it have a good spark at the plug? Put your finger over the spark plug hole and have someone hit (engage) the starter motor. Should still have some compression even with a release. Spark, air, fuel, squeeze. Has to run. Hit the basics first.

Thank you Tom3! Yes always go with basics which is what leads me to Squeeze. But...something you said "good spark plug" made me think. When I tested for spark it had plenty but the spark was orange not the usual blue that I am used to seeing....could it be a bad spark plug? Back to squeeze, i read a post somewhere that a person changed head gaskets and then had a hard time getting it to start because of the hyd. lifters ? The lifters were keeping the valve or valves from closing all the way. I did not bleed my lifters. The manual says to bleed the lifters but others on here say don't. I am somewhat confused on which is correct. Or should i even consider the lifters being the problem since they have been in the mower for a couple weeks now

I think you're on to something with the spark. Orange spark is low voltage, lots of current. Under compression that spark might disappear. Follow through on that first. A pumped up lifter can sometimes be bled down by rotating the engine until a valve is wide open, let it set overnight or so and the high spring pressure will push the oil out eventually.